# Supplementary Material (ESI) for New Journal of Chemistry # This journal is © The Royal Society of Chemistry and # The Centre National de la Recherche Scientifique, 2003 data_global _journal_coden_Cambridge 440 loop_ _publ_author_name 'Nicholas C. Norman' 'R. Angharad Baber' 'A. Guy Orpen' 'Jean Rossi' _publ_contact_author_name 'Dr Nicholas C Norman' _publ_contact_author_address ; School of Chemistry University of Bristol Bristol BS8 1TS UNITED KINGDOM ; _publ_contact_author_email N.C.NORMAN@BRISTOL.AC.UK _publ_requested_journal 'New Journal of Chemistry' _publ_section_title ; The Solid-State Structure of Diboronic Acid, B2(OH)4 ; data_newabs _database_code_CSD 202210 _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety 'H4 B2 O4' _chemical_formula_sum 'H4 B2 O4' _chemical_formula_weight 89.65 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' B B 0.0013 0.0007 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M P2(1)/c loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 7.4090(15) _cell_length_b 7.6660(15) _cell_length_c 7.0421(14) _cell_angle_alpha 90.00 _cell_angle_beta 116.04(3) _cell_angle_gamma 90.00 _cell_volume 359.39(12) _cell_formula_units_Z 4 _cell_measurement_temperature 273(2) _cell_measurement_reflns_used 672 _cell_measurement_theta_min 4.18 _cell_measurement_theta_max 26.69 _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.1 _exptl_crystal_size_mid 0.05 _exptl_crystal_size_min 0.01 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.657 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 184 _exptl_absorpt_coefficient_mu 0.162 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.877220 _exptl_absorpt_correction_T_max 1.00 _exptl_absorpt_process_details 'SADABS (Sheldrick, 1998)' _exptl_special_details ; ? ; _diffrn_ambient_temperature 293(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'CCD area detector' _diffrn_measurement_method '\w scans' _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 3854 _diffrn_reflns_av_R_equivalents 0.0851 _diffrn_reflns_av_sigmaI/netI 0.0537 _diffrn_reflns_limit_h_min -9 _diffrn_reflns_limit_h_max 9 _diffrn_reflns_limit_k_min -9 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_l_min -9 _diffrn_reflns_limit_l_max 9 _diffrn_reflns_theta_min 3.06 _diffrn_reflns_theta_max 27.48 _reflns_number_total 820 _reflns_number_gt 598 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ? _computing_publication_material ? _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0639P)^2^+0.2081P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 820 _refine_ls_number_parameters 71 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0735 _refine_ls_R_factor_gt 0.0557 _refine_ls_wR_factor_ref 0.1391 _refine_ls_wR_factor_gt 0.1261 _refine_ls_goodness_of_fit_ref 1.075 _refine_ls_restrained_S_all 1.075 _refine_ls_shift/su_max 0.000 _refine_ls_shift/su_mean 0.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group B1 B 0.5800(3) 0.9237(3) 0.0839(3) 0.0108(5) Uani 1 1 d . . . O1 O 0.5537(2) 0.74679(19) 0.0591(2) 0.0143(4) Uani 1 1 d . . . O2 O 0.7498(2) 0.97740(18) 0.2543(2) 0.0141(4) Uani 1 1 d . . . O3 O 0.2538(2) 0.94490(19) 0.2521(2) 0.0143(4) Uani 1 1 d . . . O4 O 0.0242(2) 0.74847(17) 0.0203(2) 0.0145(4) Uani 1 1 d . . . B2 B 0.0765(3) 0.9184(3) 0.0757(3) 0.0104(5) Uani 1 1 d . . . H3 H 0.292(4) 1.046(4) 0.292(5) 0.034(9) Uiso 1 1 d . . . H1 H 0.452(4) 0.711(4) -0.042(4) 0.023(8) Uiso 1 1 d . . . H2 H 0.828(4) 0.895(4) 0.334(4) 0.035(8) Uiso 1 1 d . . . H4 H 0.108(4) 0.676(4) 0.099(5) 0.037(9) Uiso 1 1 d . . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 B1 0.0105(11) 0.0084(10) 0.0117(10) -0.0006(8) 0.0032(8) -0.0018(8) O1 0.0128(8) 0.0083(8) 0.0147(7) -0.0018(6) -0.0006(6) -0.0011(6) O2 0.0116(8) 0.0080(7) 0.0124(8) 0.0011(6) -0.0044(6) -0.0001(6) O3 0.0128(9) 0.0088(7) 0.0145(8) -0.0016(6) -0.0003(7) -0.0014(6) O4 0.0131(8) 0.0057(7) 0.0154(7) 0.0002(6) -0.0023(6) 0.0011(6) B2 0.0088(10) 0.0100(11) 0.0100(10) -0.0015(8) 0.0018(8) -0.0014(8) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_2 _geom_bond_publ_flag B1 O2 1.366(2) . ? B1 O1 1.370(2) . ? B1 B1 1.715(5) 3_675 ? O3 B2 1.370(3) . ? O4 B2 1.366(2) . ? B2 B2 1.710(4) 3_575 ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag O2 B1 O1 115.77(18) . . ? O2 B1 B1 119.4(2) . 3_675 ? O1 B1 B1 124.8(2) . 3_675 ? O4 B2 O3 116.03(18) . . ? O4 B2 B2 119.5(2) . 3_575 ? O3 B2 B2 124.5(2) . 3_575 ? _diffrn_measured_fraction_theta_max 0.998 _diffrn_reflns_theta_full 27.48 _diffrn_measured_fraction_theta_full 0.998 _refine_diff_density_max 0.646 _refine_diff_density_min -0.277 _refine_diff_density_rms 0.112